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Lactose intolerance? This could be the REAL reason you can’t drink milk

Think you’re lactose intolerant? Think again. New research has found a protein in milk may be to blame for the way many of us react to dairy foods. Good news is, there’s an alternative.

Early last year, Shirley Ward’s doctor diagnosed her as mildly lactose intolerant. ‘I’d suffered for years from reflux, stomach cramps and a general ‘yucky’ feeling, particularly after having any milk,’ says the 64 year old from Walsall.  ‘I had already been told I had IBS and advised to try to eliminate dairy from my diet, so I thought milk was now completely off the menu for me.’

less than five per cent of those who think they have a lactose intolerance have been clinically diagnosed

Shirley is far from alone. One in five UK adults struggle with dairy, and like Shirley many of them assume their symptoms are due to an intolerance to lactose, the sugar found in milk. ‘However, less than five per cent of those who think they have a lactose intolerance have been clinically diagnosed,’ says leading dietitian Rick Miller, nutrition manager at A2 milk.

Now, groundbreaking new research suggests that those who avoid dairy because they think they have a lactose intolerance could in fact be reacting to a protein found in cows’ milk called A1 beta casein. Most cows’ milk in our supermarkets contains two proteins, A1 beta casein and A2 beta casein, but one type (known as a2 Milk) contains A2 beta casein protein only.

The study, published last month in Nutrition Journal looked at 600 adults who all claimed they had lactose intolerance, reporting gastrointestinal symptoms such as tummy upset, bloating, wind and diarrhoea, after drinking milk.  They were split into two groups – one group receiving milk containing both A1 and A2 proteins and the other group receiving milk containing the A2 protein only. After consuming 300ml of their allocated milk the participants’ symptoms were measured one, three and 12 hours later. At each point, those who drank the milk containing only the A2 protein showed improved symptoms compared to those who drank the regular milk containing both A1 and A2 proteins. Symptoms monitored included bloating, abdominal pain and wind.
People with IBS symptoms such as abdominal pain often put it down to lactose intolerance

An overwhelming 60-70 per cent of the world’s population report having lactose intolerance. But according to the findings of this report, the cause of their symptoms may not be lactose at all but the A1 protein in milk. ‘This is the largest human trial to date examining the differences between the impact of the A1 and A2 protein,’ says Dr Anton Emmanuel, Consultant Gastroenterologist and Director of the GI Physiology Unit at University College Hospital, London.  ‘It suggests the proteins found in dairy can have a significant impact on digestion, and that lactose may not be the only cause of gastrointestinal issues in those with an intolerance.’ Moreover, the fact that the study was done in China makes the results no less significant, he explains. ‘Given that the underlying biochemistry and symptoms of lactose intolerance are identical in Asian and Caucasian/British populations, these results are highly significant.’

This study builds on previous research from 2016 that showed similar results in a smaller group of people, also from China, says Rick Miller. ‘It means that now we may be able to question the true prevalence of lactose intolerance both in the UK and worldwide’.

Are you reacting to the lactose or the A1 protein in milk?

How do you know if the symptoms you experience after eating dairy are more likely to be a lactose intolerance or a reaction to the A1 protein in milk? You don’t, says Rick Miller. ‘If you are reacting to the A1 protein in milk, you may have very similar gut related symptoms to lactose intolerance such as bloating, stomach cramps, diarrhoea or flatulence’

‘There is no formal way of diagnosing an intolerance to the A1 protein,’ Miller continues.  ‘But if you suspect it may be causing the issue, try introducing a very small amount of a2 Milk such as a teaspoon in a cup of tea or coffee with the guidance of your doctor. If this doesn’t cause any symptoms, then gradually build up the amount.’

What is a2 Milk anyway?

‘Originally, all domesticated cows produced milk with only the A2 beta casein protein type’, Miller explains. During domestication in European herds, another milk protein emerged over time, the A1 protein, and this is now highly prevalent in Western cow herds. The irony is that all other mammal milk contains only the A2 protein, even that of humans. a2 Milk looks and tastes exactly the same as regular milk, but it’s from cows that naturally produce milk containing only the A2 protein.

For Shirley Ward, it was a welcome addition to her diet. ‘I tried lots of alternatives like Lactofree, almond milk and soy milk but never liked the taste of any of them so ended up going without, which I hated – I really missed having milk in my cereal and hot drinks,’ she says. ‘After giving a2 Milk a try, it has completely changed my life. I love enjoying it in my drinks and cooking again and I suffer with none of the symptoms I would get with regular milk. My husband loves it too, because it tastes exactly the same as the regular stuff.’

For anyone who loves milk but believes it causes them symptoms such as bloating, abdominal pain and wind, the new research will be heartening news. ‘Many people who have previously self-diagnosed as lactose intolerant could now find that it may have been the A1 protein all along causing their symptoms,’ Rick Miller asserts. ‘This new research suggests that many of these people can now return to real cow’s milk and all of its nutritional benefits.’

A2 Milk is available in most UK supermarkets at £1.39 per litre. For more information log on to

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